Depends on your definition of a "good OSS citizen." In the scary government research/mad scientist corporate research market BSD licensed code is ideal. We *can* use it, because releasing our source code would, in fact, violate either DMSO or corporate licensing arrangements.
There's more than one way to skin a cat, and frankly when our company makes something that we see as useful, but not a core product, we do release it and/or submit patches back to whence it came. I just like not having some idiot ramrodding us for not giving proprietary information out to our competitors.
(And why Tcl/Tk is under the hood of many secret squirrel projects.)